So, I've been lurking on these forums for years, using the vast knowledge here to help myself and others with various computer problems. I need some help and I can't find a solution anywhere because I'm actually kind of afraid to carry on without seeking advice.
I've built a few computers in the past few years, mostly gaming/high-end ones, and I recently built a desktop that consists of the following:
DiabloTek 650-Watt ATX Power Supply
Hitachi 500 GB SATA 3 GB 7200RPM
BFGTech GTX 260
2 x 2 GB Corsair XMS3 DDR3 RAM
LightScribe CD/DVD-RW Drive
All housed in NZXT Guardian 921RB
For a while I would notice that sometimes ( happened 3 times over about 3 months) when we'd leave and return home, the computer would have simply shut off. The first time I had to unplug the power and flip the (I guess it's a wattage selector) on the back of the PSU. I'd turn her on and she'd work fine. Well, we got home a few days ago and I did the same thing except this time I heard a lovely, loud POP and that oh-so lovely smell of electric smoke. I messed around with it a bit, dusted it out, went to do it again, and this time when I plugged the surge protector back into the wall it immediately popped again. No power button pressed. Also this time I had the side door taken off and I noticed an orange spark come from a spot near the HDD. In the Guardian, the HDD's sit sideways with the SATA connectors facing out towards the side window in a screwless bracket. This is roughly where I saw the spark.
I'd like to preserve as much hardware here as I can so I haven't attempted to plug it back in because, honestly, I'm freaked out lol. Are there any good steps to go about fixing this and not A) Killing myself or B) Burning the house down?
When having power issues replace the PSU immediately, never leave it to chance
Stay away from DiabloTek, keep with the better known name brands
If you are having power issues then seriously consider getting a UPS with good power regulation
OK: Now to answer your question;
After getting a new PSU make sure to 'bread board' the system. This means starting out with a bare minimum of hardware to POST, and then turn it off and add one piece of hardware at a time. I have had systems that have made lovely sounds and smells like you have described (generally on the first boot of a new PSU), and had no problems at all afterwards, and I have had other times where it has fried the mobo or HDD (oddly never a GPU, CPU, RAM, or ODD though it can happen), so you simply will not know if/what is dead until you start hooking it back up again.
Don't worry about fire too much, there is a lot of protection inside of the PSU to prevent such issues, but just in case keep the physical power cable handy to pull from the wall, and your fire extinguisher handy (you do have one right? And it is up to date right?). Electrical fires will not stop until after the electricity has stopped flowing, so pull the plug first, then deal with any fire if it comes to that (again, extremely highly unlikely). A grounding strap and vinal gloves can prevent self electrocution as well, but that is highly unlikely to be an issue.
So it's without a question, go ahead and replace the Diablotek? Should I stick with a 650-Watt for the system? Also, any ideas a way to make sure the 4-Pin 12V connector will have enough length on it to reach the top of the MoBo? Inside the Guardian the PSU sits at the bottom and it's a bit of a stretch around the big 260 to reach to top of the MoBo where the 12V connector is.
Almost any time you have a pop and smoke, it's the power supply. Factor in that DiabloTek makes bottom-of-the-barrel junk PSUs, and I think you've found your problem. So definitely start by replacing it with a better PSU. If you're lucky, the old one didn't take any other components with it.
650W is WAY overkill for that system. 500W is more than enough. Although if you ever want to drop in a better video card, maybe keeping 550-600W would give you some headroom. Anyway, this deal going on right now is probably about the best bang for the buck that you'll find: $39.99 after promos and rebates for a 600W unit in a trusted brand: